There is growing acceptance of transplantation across a positive crossmatch for highly allosensitized pediatric HT candidates. While survival may be similar to patients transplanted across a negative crossmatch, costs are unknown. Among 60 HT recipients at our center from 5/07 to 6/12, we analyzed hospital charges and length of stay from the day of HT to discharge and through the first year after transplant. Median age at HT was 6.2 years (15 days-20.5 years). Charges in the first year post-HT were greater for crossmatch-positive patients ($907 678 vs $549 754; P = ...

The virtual crossmatch, which is based on single antigen bead technology, is used in the prediction of crossmatch results. However, this assay differs in sensitivity and specificity from crossmatch methods. In our study, the results of physical crossmatches, performed with three different methods, were assessed against virtual crossmatch results. The aim was to determine the potential cut-off values for donor specific antibodies (DSA) that would predict the crossmatch results obtained by different methods. The results of different crossmatch techniques were correlated with the virtual crossmatch...

The flow cytometric crossmatch (FCXM) assay, which detects the presence of donor specific HLA antibodies in patient sera, is a cornerstone of HLA compatibility testing. Since relatively long FCXM assay turnaround times may contribute to transplant delays and increased graft ischemia time, we developed and validated two modified crossmatch procedures, namely the Halifax and Halifaster FCXM protocols. These protocols reduce FCXM assay time >60% and simplify their set-up without compromising quality or sensitivity...

Since the advent of the Kidney Allocation System (KAS), matched candidates with high (>98%) panel reactive antibody (hPRA) are given priority over local candidates with lower PRA. This often leads to exporting of kidneys. Data for these kidneys are not detailed on routine reports. Twenty-two organ procurement organizations prospectively submitted data from August 2015 to July 2016, describing allocation practices of kidneys to hPRA patients and outcomes of these kidneys. Five hundred twenty out of 6924 procured kidneys were exported for hPRA recipients...

The definition of anti-HLA antibody profile in highly sensitized patients on a waiting list is crucial when virtual crossmatch is used in organ allocation systems, but also when used to identify the true deleterious anti-HLA antibodies. Here we propose different levels of risk based on the results of anti-HLA antibody testing in neat serum (N) and after sera dilution (DIL) and C1q test in 18 highly sensitized patients. This group was heterogeneous in terms of anti-HLA antibody titers and their ability to fix complement...

PURPOSE OF REVIEW: Sensitization to human leukocyte antigens (HLAs) limits access to potential donors and contributes to inferior graft survival after transplantation. In this article, we will review the effects of HLA-specific antibodies on intestinal transplant outcomes, and discuss considerations in the monitoring and treatment of anti-HLA antibodies. RECENT FINDINGS: Only a handful of studies has investigated the effects of donor-specific anti-HLA antibodies (DSAs) on intestinal allograft outcomes...

Soon, a virtual crossmatch shall replace the complement-dependent cytotoxicity (CDC) allocation crossmatch in the Eurotransplant region. To prevent positive CDC-crossmatches in the recipient centre, careful definition of unacceptable antigens is necessary. For highly sensitized patients, this is difficult by CDC alone. Assignment of all antibodies detected by sensitive assays, however, could prevent organ allocation. To assess the usefulness of the Luminex C1q-assay to prevent positive CDC-crossmatches, all CDC-crossmatches performed prior to deceased kidney transplantation in a 16-month-period were reviewed...

This review outlines the development of human leukocyte antigen (HLA) antibody detection assays and their use in organ transplantation in both antibody screening and crossmatching. The development of sensitive solid phase assays such as the enzyme-linked immunosorbent assay technique, and in particular the bead-based technology has revolutionized this field over the last 10-15 years. This revolution however has created a new paradigm in clinical decision making with respect to the detection of low level pretransplant HLA sensitization and its clinical relevance...

BACKGROUND: Kidney transplantation in highly-sensitized (HS) patients can improve with organ-exchange strategies based on virtual crossmatch (V-XM). Experience in very-HS patients is limited. METHODS: In June 2012, Andalusia started a V-XM protocol for very-HS patients (calculated panel reactive antibodies ≥95%). After organ allocation a cytotoxic-XM performed immediately before transplantation had to be negative for surgery to proceed. We analyzed results up until December 2015...

Access to kidney transplantation for patients with high levels of antibodies against HLA is a major challenge. This issue makes it difficult to detect compatible donors for those patients in a certain geographical area. Consequently, hypersensitized patients remain on the waiting list for long periods and their quality of life deteriorates. Our purpose was to increase access to transplantation for highly sensitized patients by developing a national priority allocation system based on virtual crossmatch. Between June 15, 2015, and May 15, 2016, 675 patients on the kidney transplant waiting list with calculated panel-reactive antibodies ≥98% and undergoing dialysis for at least 12 months were included in the study; 86...

Efficient allocation of deceased donor organs depends upon effective prediction of immunologic compatibility based on donor HLA genotype and recipient alloantibody profile, referred to as virtual crossmatching (VCXM). VCXM has demonstrated utility in predicting compatibility, though there is reduced efficacy for patients highly sensitized against allogeneic HLA antigens. The recently revised deceased donor kidney allocation system (KAS) has increased transplantation for this group, but with an increased burden for histocompatibility testing and organ sharing...

OBJECTIVES: Human leukocyte antigens and HLAspecific antibodies are important before and after transplant treatment. The determination of the alloantibodies before transplant is useful for the estimation of risk for antibody-mediated rejection. Virtual crossmatch uses solid-phase assay to detect anti-HLA antibodies and allows exclusion of donors with unacceptable HLA antigens. The aim of our retrospective study was to investigate HLA class I and class II alleles and panel reactive antibody and Luminex Corporation (Austin, TX, USA) single-antigen bead assay positivity frequencies in the Southeastern region of Turkey...

Deceased donor kidney allocation was reorganized in the United States to address several problems, including the highly sensitized patients disadvantaged with large, diverse repertoires of antibodies. Here, five transplant surgeons review their center's experience with the new allocation changes: highlighting areas of accomplishment, opportunities for improvement and, in some cases, stark differences in practice. Across these five centers the highly sensitized patients (CPRA ⩾98%) range from 5.5 to 9.2% of the 12,364 candidates on their collective waitlist...

BACKGROUND: Single antigen beads (SAB) are used for monitoring HLA antibodies in pretransplant and posttransplant patients despite the discrepancy between virtual and actual crossmatch results and transplant outcomes. This discrepancy can be attributed to the presence of conformational variants of HLA-I on SAB, assessment of which would increase the concordance between SAB and flow cytometry crossmatch (FCXM) results, thus enabling improved organ accessibility for the waiting list patients and a better prediction of antibody-mediated rejection...

BACKGROUND: The compatibilities between donors and recipients are extremely important for evaluating the immunological risks of transplants. One challenge faced by data analysis tools is the transformation of complex data into simple, intuitive, and important information that can be used to resolve contemporary problems. To address this challenge, we developed the EpViX software to perform epitope reactivity analyses and automated epitope virtual crossmatching. EpViX is a facilitator of medical decision-making regarding the identification of the best donor for a high-immunologic risk recipient...

PURPOSE OF REVIEW: Recent reports on donor-specific antibodies documented an overwhelming frequency of antibodies to one specific locus - human leukocyte antigen DQ (HLA-DQ). This article provides a short summary of clinical observations, a historic perspective to account for the late recognition of the role of HLA-DQ antibodies as well as potential explanations. RECENT FINDINGS: The basic understanding of the complexity of HLA-DQ molecules (antigens and antibodies) existed already 3-4 decades ago...